<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Title</title>
    <style>
        [v-cloak]{
            display: none;
        }
    </style>
</head>
<body>
<div id="app" v-cloak>
    <input type="text" v-model.lazy="message">
    <h2>message:{{message}}</h2>
    <hr>
    <input type="text" v-model.number="counter">
    <h2>counter:{{counter}}-{{typeof counter}}</h2>
    <hr>
    <input type="number" v-model="counter2">
    <h2>counter:{{counter2}}-{{typeof counter2}}</h2>
    <hr>
    <input type="text" v-model.lazy.trim="content">
    <h2>content:{{content}}</h2>
</div>
<script src="https://unpkg.com/vue@3"></script>
<script>
    const app=Vue.createApp({
        data(){
            return{
                message:'Hello World!!!',
                counter:0,
                counter2:0,
                content:''
            }
        },
        watch:{
            content(newVal,oldVal){
                console.log("newVal:",newVal)
            }
        }
    })
    app.mount("#app")
</script>
</body>
</html>